Pipe molding apparatus



P 6, 1932- E. G. JONES PIPE MOLDING APPARATUS Filed Aug. 15', 1936 a Z j a 1% L a}? 1M W- H? Patented Sept. 6, 1932 UNITED A STATES- AT]; A

EDWARD enonen JONES, on vn-nnENIer e, TimNsvAAD, UNION OF sournnrmcn PIPE noLDING APPARATUS Application filed August 15, 19 0, Serial No. 475,522, and in, the Union of South Africa Septemberm, 1929.

The present invention relatesto themanu- "facture of pipes from plasticmaterial and Iusual extrusion methods are defective by reason of the laminations which appear in the body of the pipe. The laminations diminish the mechanical strength of the pipe by reason ofthe'imperfect cohesion at the faces of the laminations; andcause blisters to form during thefburning operation, on account of whicha large proportion of the pipes now made have to be'di'scarded'.

It is believed that there are two principal 5 causes of laminations, viz. the frictional resistance of the clay against the surfacesvof the die or other fixed parts over which it flows, causing the flow of external layers of clay to be retarded as compared with the internal layers, and the degree of dryness of the plastic clay which is found to be necessary in order that the extruded body of clay may be reasonably self-sustaining.

The object of the present invention is to produce a denser and more homogeneously shaped pipe than that produced in the present pipe making Inachin'e,u

and the progressive extension of the mold cavity produced. by opposing the extension of the mold by a. constantly applied force which is overcome by the pressure of the material within the mold cavity. I a I According also to this invention apparatus for carrying out the method comprises an elongated nozzle through which the plastic material is forced under pressure, an annular moldcavity provided by an outer mold casing which surrounds and slides on the nozzle and an inner central core member the upper of the clay contributes to'the welding of the height by brake mechanism 7 which looks end of whichforms an annular orifice during the moldlng operation, means for {forcing the plastic'material intothe'mold cavity and further means yieldingly opposing the'rela tive extension of the moldcasing and the a nozzle so as to maintain the material in the mold cavity under pressure. 7 v i The pressure towhich'the plastic material is subjected as it is deposited in the mold cav ity tends to weld together any incipient laminations which may have been set u durin its flow into. the mold. Moreover t e .mol

support for the mass: confined Within the mold, so that inmaking clay pipes avwetter mixture can be used thanthatwhich is neces-' casing and central core provide mechanical j sarywhen the clay is extruded in'totheopen air and has therefore to befstiif enough toib'e self-supporting; and this increasedwetness laminations.

The production oflaminations is additionally avoided by the arrangement of the nozzle above described wherebythe plastic material is deposited without move ent along. the

outer wall of the mold.

The invention is? illustrated in the accom panyingdrawing in which 1 i Fig. I is a partly sectioned elevation of a I Fig.'II shows a portion ofFig. I with themovable 'parts in a different position; I

InFig. I there are shown certain parts of the known'type'of pipe extruding machine comprising a frame-'workfl which guides a vertically sliding table3. The table is yieldingly supported chains *4 passing over pulleys 5 an'd'provlded with counterweights 6. 'The table can'be'secured at any desired 7 9 forms 'withfsaid core memberthe annular orifice 12 through which an annular rfod of clay downwardly throughfthe clay is forced into the mold cavity 13 pro- I vided between the core member 10 and the mold casing 14. Said casing is of the necessary length and form to contain the completed raw pipe. For making a socketedpipe,

Qlay is torceddown through the nozzle 14; thepress 8 and fills thebell 15 in byflowwing th rolgh thebell car ity in the. ordinary manner; the usual spew holes being provided as by ra sing the mold. on spaced blocks l8; Upon. the cwvity oifthe :bell, being filled, the formationotfthe' pipe proper in the novel manner begins by: the entry of the clay into the mold cavity 13.;

The p -res sure of the clay-l is resisted by the l mold casing 14 thecorelQ and the table.3. .Only the latter 'canyield and does so by l descending but only in the, circumstance that the clay in the mold cavity isrunderthe presv p y 7 V sure necessary to lift the countervveights 6. -l In testnnony'yvhereof I atfix my signature. :95

7 *These ,vveightsar e tor this purpose made heavier than in the. present practice;- and it accompanies its drying renders it readily removable from the mold.

I claim V 1. In a pipe makingmachine the combination of a press, an elongated nozzle through which plastic material is forced by the press, a core arranged co -axially with the nozzle and so that its upperend forms; an annular die with said nozzle, a mold casing surrounding and slidable lengthwise over the nozzle,

and yielding means forsu-pporting said casing against sliding movement over said noz- "zle, the core extending through said means,

being longer than the mold casing and being adjustable-to enable it to be Withdrawn from the mold casing; 1- 1 2. In a pipe'molding machine. the combination of apress, anelongated nozzle. through which the plastic material is forced hyth'e press, a mold cas ng surrounding, Said nozzle and movable axially relativelythereto yield- 7 ing means supporting said. casing against sliding movement over saidnozzle and a, cen} tral core-member extending through said means an d arran ed to: be stationary while the mold isbeing'filledjso asto. occupy the hole length of the mold casing at the coiilplet-ion of theinolding operat on and remow able tov withdraw it: from the molded pipe EDWAR GE-Q JONES has beentriangle-suitable to make them suf- Ificiently "heavy to maintain t e clay 'vvithin 'ap fe s e o about as'ipounds P61 quare inch. 7 I V 1 y The continued. fiowof; clay'frorn the nozzle 7 I 14: idrivesthe table doiwn wardsgand the mold I casing, 14 moves doiv n withthetable 3, there- -by sliding downfover thenozzles- That is to sayyas each small portion oi clay passes from nthe' nozzle it is 'de )osited Within the mold s casing in its proper-position therein anddoes nst thereafterimove relatively thereto. As I'll. the-force acting to fill the mold'cavityand 7 ,the. force resistingl'thefilling are cont-inn one and snbstantiall yconstant, each small same degree'of pressure sothat the pipe maportion of olay'is. also deposited under the .f i

.terial is densely and uniformly, gpacked 7 throughout the 5 length of the V pipe Finally the mold passes oil-the nozzle as I showneinuFig. 11;; Clay spews outof the "gap between them, whereupon the press is stopped and the brakes 7. are fapplied to pre- 7 next Withdrawn from the lower end of the mold casing as indicated by the dottedlines 'ltla -lligf II. The mold casing containing the formedrpipe is removed from the table and -from; the socket former 1.6- and placed H inaipos tion for drying; the mold. serving ing the raw pipe during transportationand vent thetab-le fromf-rising. The coreelOis f lfp r P tes g s p'pe 

